High Wire Rod Limitation Law Research

In this paper the various regularities in mechanical property of 70G and H08Mn2SiA wire rod which placed in nature temperature at different time are studied. The conclusion of test is that the wire section shrinkage rate have been improved obviously with the time and in the former three days the section shrinkage of 70G has been improved very obviously, and became stability after parking six days.The former six days the mechinical property of H08Mn2SiA wire rod has been improved largely and the yeildstrenght,resistance to tensile stress,elongation became stability after parking six days.But the section shrinkage still improve and became stability after parking ten days.Therefore the wire rod of 70G should been parked more than three days before thery get further working and H08Mn2SiA should been parked more than six days.It's found that the affect of mechanical property of 70G is very complex ,inclouding residual stress,the content of hydrogen and microstructure, different park time and so on.And the improvement of H08Mn2SiA's mechanical property primarily depends on the released residual stress.